A scientist evaluates the Galileo affair

Page 86 from "The Imagined Conflict"

A persistent myth is that Galileo's observations (see image) were proof that the Earth revolves around the sun. Galileo himself knew very well that he did not have a very good case scientifically for this hypothesis. He tried to advance an erroneous argument based on the tides, but his "Tidal proof" convinced few at the time and is actually incorrect.

In chapter 3 of “The Imagined Conflict” (Wipf & Stock, 2025), a major part is entitled “Galileo was right and so were his critics”* (pp. 85–102). My claim is that this chapter has one of the most accessible and comprehensive accounts available about the science at the time of Galileo. Unique for the book in this genre is also that it has 41 figures and illustrations, 11 of which are in chapter 3.

The chapter about Galileo contains a scientist’s view of the science of his time, and steers away from a presentist view of history. It is based on research from the last 15–20 years where we have obtained a much better understanding of the limitations of the science of the solar system of the 17th century. 

I claim that it is impossible to understand the Galileo affair without understanding why the geo-heliocentric model of Tycho Brahe, ignored by Galileo, had better scientific support at the time. In his book from 1632, Dialogue Concerning the Two Chief World Systems, Galileo completely ignores this system. He only pits the old Ptolemaic system, abandoned by most already in 1632, against the Copernican system. However Tycho's geo-heliocentric system was considered the scientifically best one for several decades after Galileo’s death. This is hard to understand with a presentist view of history, where the past is understood in light of present knowledge. 

The chapter also discusses other factors of importance in the Galileo affair. First, it happened at a critical moment during the thirty-year war when Rome and the Catholic church were under threat as Swedish troops in Germany were close to have crossed the Alps into Italy. Second, Galileo was telling the church how to interpret the Bible with respect to cosmology in a way that might have been acceptable for a Protestant layman, but definitely not a Catholic one. Third, Galileo asserted that someone had edited his letter about the Bible and made it look worse than he intended. In 2018 the original was found, and showed that Galileo's original was the offending one, and that the edits were in Galileo's own handwriting in order to make it look milder to avoid problems. Galileo cannot have been a very easy person to be around!

The chapter ends by saying "The Galileo affair is a result of projecting the Enlightenment image of conflict between faith and science back in time and distorting history in light of it. That is a very unfortunate way of dealing with the history of science."

* Title from Olson, “Galileo was Right—But So Were His Critics”.